Anti-inflammatory effects of non-antibiotic alternatives in coccidia challenged broiler chickens

This study was conducted to determine the effect of selected antibiotic alternatives on growth performance and inflammatory gene expression in broiler chickens challenged with Eimeria oocysts from Coccivac® vaccine. A randomized complete block design with 6 treatments and 8 replicate pens per treatment was used. The treatments were; negative control (NC) with neither antibiotic nor antibiotic alternatives, Salinomycin positive control (PC), essential oil (Orego-Stim®), commercial yeast (AlphamuneTM), direct fed microbial (Avicorr®) and crude yeast extract. The study lasted 42 d and measurements were taken on d 0, 21 and 42. There was no significant difference in body weight (BW), daily gain (BWG) between treatments on d 21. From d 21 to d 42, BWG of birds treated with Salinomycin (2058 g) was higher (P<0.05) than Avicorr (1919 g) and Orego-Stim (1933 g) treated groups. Feed efficiency (g/kg) was improved (P<0.05) by Salinomycin (605) compared with NC (578) and Orego-Stim (578) treatments. Immune-related genes, interleukin-6 (IL-6) and 10 (IL-10), lipopolysaccharide-induced TNF-α factor (LITAF), toll-like receptor 4 (TLR-4) and interferon γ (IFNγ) were measured by PCR. On d 21, expression of IL-6 was reduced (P<0.05) in the Salinomycin, Avicorr, Alphamune and Orego-stim treatments relative to the NC and the crude yeast treatments. On d 42, LITAF was lower (P<0.05) in the Orego-Stim treatment group than NC. Birds in the crude yeast treatment had higher (P<0.05) expression of IL-10, IFN-γ and TLR-4 compared to the Orego-Stim treatment, but similar to NC. For digestibility trial, Salinomycin and crude yeast treatments had higher apparent ileal dry matter (DM), energy, N and P digestibility on d 21. These differences were not apparent on d 42. Overall, these results confirm the expected improved animal performance with antibiotic (Salinomycin) and further show reduced inflammation in the cecal tonsils with organic acid (Orego-Stim) treatment in broiler chickens.